1. Field of the Invention
This invention relates to a silicon-based functional matrix substrate and an optical integrated oxide device, especially suitable for use in optical integrated oxide electronics spread out on silicon.
2. Description of the Related Art
It is a well-known fact that oxide thin film materials have been remarkably developed in recent several years, starting from high-temperature superconductive oxides reported in 1986 ((1) Z. Phys. B., 64, 189-193(1986), (2) MRS Bulletin, XVII, No. 8, 16-54(1992), (3) MRS Bulletin, XIX, No. 9, 21-55(1994)).
On the other hand, memory devices using ferroelectric materials, which were energetically studied in a certain period of 1950s ((4) Electrical Engineering, 71, 916-922(1952), (5) Bell Labs. Record, 33, 335-342(1955)) but failed to penetrate into industries because of difficulties in, for example, controlling interfaces, have recently come to be highlighted, and researches and developments thereon have progressed rapidly. The current aspect of the ferroelectric nonvolatile memory devices were reported in detail (for example, (6) Appl. Phys. Lett., 48, 1439-1440(1986), (7) U.S. Pat. No. 4,713,157, (8) IEDM Tech. Dig., 850-851(1987), (9) IEEE J. Solid State Circuits, 23, 1171-1175(1988), (10) Tech. Dig. ISSCC 88, 130-131(1988), (11) Applied Physics, Vol. 62, No. 12, 1212-1215(1993), (12) Electronic Ceramics, Vol. 24, Jul., 6-10(1993), (13) Electronic Materials, Vol. 33, No. 8(1994) (Special Vol. entitled "Application of Ferroelectric Thin Films to Nonvolatile Memory"), (14) Ceramics, Vol. 27, 720-727(1992)).
It is needless to say so on oxide superconductive devices (see Literatures (2) and (3)), it is well known also that researches and developments have been proceeded recently on applications of oxide nonlinear optical devices and elements, as well. While fields of superconductive devices and ferroelectric nonvolatile memory devices are under remarkable development, in the field of optical devices, conciliation with lithographic techniques favorably used for silicon devices has not been prosecuted, as shown by the fact that bulk materials are still used, for example.
The Inventor, however, has recognized formerly that the importance of epitaxial thin films of oxides on silicon is not limited only to superconductive devices or ferroelectric nonvolatile memory device, and made some reports or proposals on oxide stacked structures made by stacking oxide thin films on silicon substrates and ferroelectric nonvolatile memory devices using them ((15) Japanese Patent Laid-Open No. Hei 8-330540, (16) Japanese Patent Laid-Open No. Hei 8-335672, (17) Japanese Patent Laid-Open No. Hei 8-340087, (18) Japanese Patent Application No. Hei 8-336158, (19) J. Ceram. Soc. Japan. Int. Edition, 103, 1088-1099(1995), (20) Mater. Sci. Eng. B., 41, 166-173(1966).
On the other hand, in optical integrated oxide electronics, it is required to integrate a semiconductor laser or other semiconductor light emitting device together with an oxide optical device or other oxide device on a common substrate. However, as far as the Inventor is aware, there has been almost no substantial report on concrete device structures. Especially on optical integrated oxide devices in which oxide elements are formed by epitaxial growth of oxides, no report has been heard of.